Planetary change-speed gear



1952 R. c. CLERK PLANETARY CHANGE-SPEED GEAR Filed Nov. 1'7, 1949 ATry-S' Patented Jan. 1, 1952 PATENT OFFICE This inve tion relates toplaiietafi' milit s-a transmission of the type having compounded" s' r' e .uv.

Arr objectiof this invention toprovide'a form ofiplanetary multi speedgearinwhichthetrans mission trains' can befof'thesimpl'e type c'or'1"sis"t1-' ing ofa sun wheel, an annulusgearandplahfe't wheels each meshing with the' sun wheel andflthe ahnfulusi gear; which embles' the des gn-thine easii'y modified in order to; vary the gear" ratios available;- andiwhieh provides high" emcienciesf withoutthe use of heavily loadedelements'run nin'g at speeds which" are high" relative to the speedoftli'e driving element ofjthegea'i'ing. m I Ahotherolij ect isfto provide a"clo'sep-'ratiofmu speed transmission especially suitable" for use the main power transmission systems'of venues? drivefrl byiinternal-combusti'on engines; s ower object: is toflprovide" a tran'srnission which is reasonably'compact and light and which crder w: establish each of severalflspeed ratios; Another object is to" enable a t: nsrniss'ion having the foregoing features to beelectricallycono q The-accompanyingdrawing is ai'jse elevation of ah'jexample' ofa transin struct'ed in accordance was theinve' use on automobiles and yi'eldi'ng five-forward speed ratios and areverse ratio between a driving element and a driven element. The transmission includes a first planetarygear train having an m ess se QQuPl to the d i n ele-r merit, a sun wheel serving as a reaction element,

and a planet-carrier coupled to the driven ele ment and carrying planet wheels each meshing with the annulus gear and" the sun wheel, a sec speed ratio, a controllable friction hrake for ar resting. rotation: of the 'sun wheel of the second? train and thereliypa'using' these trains to operate compounded and; to? yield an overdriiler speed ratio; and friction ,clutchmeans 'adaptedtolook these trains: solid "by coupling together the sun: wheel'and thev planet-carrierof: the second itrain to yield direct drive; The transmissionwalso-includes a third planetary gear train havingisan' nu lusse n cu edtcthe nlanetecarrier of the first train," a'sun wheel coupled to the sunwheel me J 2 V of the first train, and a planet-carrier serving as a reaction element and carrying planet wheels each meshing with the annulus gear, and the sun wheel, and a controllable friction brake for arresting rotationof this planet-carrier and thereby causing the first and third trains to operate compounded and to yield a low-speed ratio. A founthplanetary gear trainhas'an annulus gear I serving as a, reaction member, asun wheel 10 carriercoupl'ed to thedriven element and carrying planet wheels, each meshing with the annulus gar andth'e sun wheel, and acontrollable frictiongbr'ake for arresting rotation of this annulus gear and thereby providing an emergency low gear by the aid of the fourth train alone. A fifth planetaryfgeartrain, adaptedto yield a reverse ratio has a"- sun wheel coupled to the driving element. an annulus gear coupledito the driven o elementia'rida planet-carrier serving as a reaction element: and carrying planet wheels each m shing with the annulus gear and; the sun wheel and a controllable friction brakefor arrestingf rotation; of this planet-carrier. ,A 'gear'case consists of frontand back cupped castings" Inf and Il having flanged lips and fixed together mouth to mouth by bolts and studs such L2'1and 1'3 passingthrough or engaged in the A" drivingshaft l l, having'itsvfront end y a} bearing; not shown is supported in 7 I5 housed inf a diaphragm wall" It fixed d atlt's frontend by a bearing I8 ir'i'thefdriv ngsliaft M and at its rear end' by a 9 inith e l'f fiil d'wall Of the gear case. fIlhje abovementioned five planetary gear trains are ranged one behind another j in the .rSt, third and second. RercarrierandA the annulus gear, these references in each case being preceded by the numerah[L2]v 3, 4 or 5 identifying. the number ofthe train Allthecontrollable brakes andthe clutch are constituted by, e lectromagnetically operated' frictio n devices-includinglan annular electromagnet' of channelgsection adapted to be frictionally errgaged with i an annular armature.

' The. annulusgear IA is me rearwardly openby' splines'i2l to an internally sp'linedrear end portion oflthe driving shaft- 'lihe-planeti-carrier' IC includesa disk" fixed to the driven shaft and coupled tothe-drivingvelement, and a planethigfear case art It. A driven shaft it -fromffront to'rear of the gear e" sun wheel; of each train,- C

having rearwardly projecting pins carrying the planet pinions such as 22. A rearward extension of the planet-carrier IC is rigid with the annulus gear 3A of the third train. The planet-carrier 30 of the third train is connected at its rear part to a cage disk 23 forming part of the rotary element of the brake that is engaged to establish the low speed (second gear) ratio.

The sun wheels IS and 38 of the first and third trains are integral with a hollow shaft 24 journalled on the driven shaft and capable of a limited sliding movement on this shaft; to the rear end of the shaft 24 are fixed the armature 25 of the underdrive (third gear) ratio brake and the annulus gear 2A of the second train. The planetcarrier 20 of this train includes a disk having a hub 23 splined to the driven shaft, the disk being placed in front of the train. The sun gear 28 of the second train is rigid with a short hollow shaft 21 which is journalled on the hub '26 and capable of a limited sliding movement on this hub. Integral with the rear end of the hollow shaft 21 is an armature 28 which is used for the overdrive (fifth gear) ratio brake and also for an electromagnetically-operated friction clutch used for establishing the direct-drive (fourth gear) ratio.

The sun wheels 48 and S of the fourth and fifth trains are integral with the hollow shaft 20. The part of the planet-carrier [C of the first train that extends to the annulus gear 3A is keyed at 29 to a cylindrical shell 30 extending forward around the annulus gear of this train and fixed to the rear part of the planetcarrier 40 of the fourth train. The annulus gear 4A of the fourth train is coupled to a cage disk 3| forming part of the rotary element of the brake that establishes the emergency low (first gear) ratio. The annulus gear 5A of the fifth (reversing) train is a forwardly opening drum forming a front part of the planet-carrier 40 of the fourth train. The planet-carrier 50 of the fifth train includes a cage disk 32 forming part of the rotary element of the reverse train brake.

The three brakes that are engaged respec-' tively to establish reverse, emergency low and low speeds are of the torque-assisted type forming the subject of my patent application, Serial No. 34,781, filed June 23, 1948. The cage disk 32 of the reverse-speed brake carries three or more uniformly distributed balls, such as 33, mounted in cylindrical bores, such as 34, in the disk, so that they are constrained to slide in directions parallel to the gear axis.v Two friction rings 35 and 36 are disposed between the cage disk 32 and respectively the diaphragm wall l6 and the concentric annular pole-pieces of a U-section ele'ctromagnet R which is locked in the gear case by dowels such as 31. Each of the balls 33 co-operates with two conical camming pockets, such as 38 and 39, in the rings 35 and 36 respectively.

The emergency low speed brake is arranged similarly to the reverse brake, and include friction rings 49 and 4| between its cage disk 3| and respectively the back of the magnet R and a fixed annular electromagnet EL located by dowels such as 41. Likewise the low speed brake includes friction rings 42 and 43 between its cage disk 23 and respectively an annular electromagnet L formed on the back of the magnet EL and a fixed friction ring 44 clamped between the two parts of the gear case. In each of these brakes the two rotary friction rings are tied together by spring tension links, such as 45, and fitted with disengaging spring plungers, such as 46, which also act as dowels constraining the two rings to rotate together, as described in detail in my said patent application.

The armature 25 co-operates with a fixed annular electromagnet U located by dowels, such as 41, and the armature 28 co-operates alternatively with an electromagnet 0 formed on the back of the magnet U and with an annular electromagnet D carried by a disk 48 having a hub 49 splined to the driven shaft I'l. Each of the brake magnet windings has one end grounded and the other end connected to a separate terminal (not shown) The clutch winding has one end groundedand the other connected to an insulated slip ring 50 cooperating with a brush mounted in a brush-holder terminal 5|. A control switch (not shown) enables any of the magnets to be energised one at a time.

The lower half of the gear case has double walls which contain an oil sump 52. Holes such as 53 form oil passages between the sump and a pump compartment. An oil circulating pump consists of a vaned impeller 54 fixed to the driving shaft I4 and operating in an annular channel formed between the front wall of the gear case and a pressed sheet metal ring 55 clamped at its periphery by the diaphragm member I6. Oil enters the pump through the hole 53 and a port 56 in the ring 55 and is forced by the impeller 54 through a delivery port 57 and a duct 58 to an annular chamber 59 in a plain bearing formed in the front wall of the gear case. Radial ports 60 in the driving shaft I4 lead from the chamber 59 to an axial bore 6-l in this shaft, whence the oil is delivered through an axial bore 62 and radial bores 63 in the driven shaft ['1 to various parts of the gearing. scavenging of the gear case proper to the sump is effected by the rotating magnet D and the cage disk 32 which pick up surplus oil and fiing it into holes or slots leading tangentially from the gear case proper to the uppermost part of the sump at the side where the peripheries of the parts D and 32 are moving downwards.

In the example shown all the annulus gears have sixty-one teeth; the suns IS, 4S and is have twenty-three teeth; the suns 2S and 38 have twenty-nine teeth. The following are the speed ratios obtained.

When the driving shaft I4 is rotating, and when the driven shaft 11 is held stationary by the load, no magnet being energised, annulus gear 5A and planet-carrier 4C are held stationary through parts 39, 29 and 10. Since suns 5S and 43 are rotated directly by the driving shaft, cage disk 32 is driven idly forward and cage disk 3| idly backward. If new magnet R is energised, ring 36, acting as an armature, is drawn into frictional engagement with magnet R so that rings 35 and 36 are caused to lag in relation to disk 32. Balls 33 accordingly ride up the camming pockets 38 and 39 and force these rings axially apart into full frictional engagement with parts It and R, so that the rotation of disk 32 is arrested and consequently annulus gear 5A is driven backward at a reduced speed, taking with it the driven shaft. g

The emergency low and low speed brakes opi l-58 L 56 eratesimilarly to; the reverse brake-t the. other brakes; and the clutch are more lightlyloaded and are therefore not of the torque-assistedtylle.

When magnet. EL only is, energised, annulus gear 4A is held stationary, and gear train 4 operates as a simple wide-ratio underdrive planetary; unit. When magnet L only is energisedLpIanel -Garrier; 3C is thereby held stationary.v Annulus gear i Ais directly driven by the drivingshaft, sothat sun IS is urged to rotate, backward and; planetcarrier 1C and with it annulus gear3Aareurged to, rotate forward. Since. planet carrier 30 fixed, sun. 38 is urged to rotate. backward. with sunlS; Trains, I and 3 therefore operate. coinpounded to impart a forward. rotation-to; he drivenshaft at lowspeed: v When magnet, U 0n]y'is:energised',..s un' Is; is thereby held stationary'and .trainl operatesas a simple close-ratio underdrive planetaryv unit. When clutch, magnet D; only -is' energised, sun 2S-isclutched to planet-carrierZC so thattrain 2-is locked solid and so locks'sun IS to the driven shaft; train I is therefore also locked solid so that its annulus gear i A, which is directly driven by thedriving shaft, drives the driven shaft directly.

When magnet 0. only is energised, sune2s. is thereby heldstationary. Planet-carriers tC-and 2C: are constrained to" rotateforward with the driven shaft. Driving torque is applied to the drivenshaft by train I, the reaction of which is a; backward torque on the suniis; For-ward rotationimparted by this. driving torqueto-the driven shaft causes annulus gear 2A and'with it sun IS to be rotated forward faster than the driven shaftthe efiective torque onthe driven shaft being that applied through the: planet;- carrier lC less that applied through the-planetcarrier: 2C. Thus trains l and 2 operate compounded to impart to the driven shaft a speed exceedin that of the driving shaft.

The. term coupled usedinxthe following claims means that the two; elements so. de-.. scribed are incapable of relative rotation at least in normal'operation of the gearing on a ratio requiring such coupling; thisterm does not howeverexclude theuse of a connection whichiis disengageable; in particular" circumstances; e; g. a free-wheel coupling;

I claim:

1. A planetary multi-speed transmission. including a, driving element and adriven element, a. first planetary gear. train? having an annulus gear' coupled to the driving element, a sun wheel serving as a reaction element, and a planet-carrier coupled to the driven element and having rotatably mounted thereon planet wheels each meshing with the annulus gear and the sun wheel, a second planetary gear train having an annulus gear coupled to the sun wheel of the first train, a sun wheel serving as a reaction element, and a planet-carrier coupled to the driven element and having rotatably mounted thereon planet wheels. each meshin with the annulus gear and the sun wheel, a controllable stop for arresting rotation of the sun wheel of the first train to yield an underdrive speed ratio, a controllable stop for arresting rotation of the sun wheel of the second train and thereby causing these trains to operate compounded and to yield an overdrive speed ratio, and clutch means capable of locking these trains to yield a 1-to-1 ratio drive.

2. A transmission as claimed in claim 1, whereinJsaidclutch-means:are capable of coupling to"- gether; the-sun wheel and. the planet-carrier of thesecond train.

3. A transmission; as-claimed: in claim 1-,. and including a third planetarygear train havingan annulus gear coupled. to the planetz 'carrien of thefirsttrain. a sun wheel coupled to the: sun wheel ofthe. first train, and a planet-carrier serving; as. a reaction-element and having ro tatablymounted thereon planet wheels each meshing. with. the.. annulus gear and the sun wheel, and a controllable stop for arresting'rotationof the planet-carrier of: the third train andthereby causing: the; first and third trains to operate compounded-and tol yield a low speed ratio.-

4i, transmission as claimediin clain'r '1, and

including. a furthenFpIanetary gear t'rainhaving.

an. annulus. gearserving as: a; reaction member, a sun wheel coupled to i the 2'driving element; and a planet-carrier coupled to 'thedriven element and having. rotatably m'ounted thereon planet wheelsteach meshin with theannulus gear and the sun wheel-,and a controllable stop ror arresti-ng rotation of the-last-mentioned annulus gear and thereby providing'an emergency low" gear by theaid of said further train alone.

5.; A transmission asiclaimedin claim 1 and including a planetary gear: train adapted to yield. a reverse-ratiov and having a sun wheel coupled-to the' driving element, an annulus gear coupled to. the driven element," and" a planetcarrier serving as aj-reaction element and having rotatably. mounted thereon: planet wheels eachmeshingwith the annulus gear and the sun'whe'elj and a controllable stop for arresting-rotation of the planet-carrierof the reverse train.

' 6. ,A. transmission as claimed in claim 1; and including-.athird planetary gear train havingan annulus gear coupled to the'planet-carrier of, the first train; .aj-sun wheel coupled to the sun wheel of the first train; and a planet-carrier} serving as. a reaction element and having rotatablymounted. thereonplanet wheels each meshing: with thelannuluszgeanand thesuni wheel, a controllable stop for arresting-rotation or the plane-carrier of: the tliird train and therebytcausing the first and third trains-= to operate compounded and to yield a low-speed ratio, afourth. planetary gear train having an annulus gear serving'as a reaction member; asun wheel coupled to thedriving element, and a planetcarrier coupled to the-driven element and having rotatablyi mounted thereon planet" wheels each meshingwithithegannulus gear and the sun wheel, and a controllable stop for arresting rotation of the annulus gear of said fourth train and thereby providing an emergency low gear by the aid of the fourth train alone.

7. A transmission as claimed in claim 1, and including a third planetary gear train having an annulus gear coupled to the planet-carrier of the first train, a sun wheel coupled to the sun wheel of the first train, and a planet-carrier serving as a reaction element and having rotatably mounted thereon planet wheels each meshing with the annulus gear and the sun wheel, a controllable stop for arresting rotation of the planet-carrier of the third train and thereby causing the first and. third trains to operate compounded and to yield a low-speed ratio, a planetary gear train adapted to yield a reverse ratio and having a sun wheel coupled to the driving element, an annulus gear coupled to the driven element, and a planet carrier serving as a reaction element and having rotatably mounted thereon planet wheels each meshing with the annulus gear and the sun wheel, and a controllable stop for arresting rotation of the planet-carrier of the reverse train.

8. A transmission as claimed in claim 1, and including a third planetary gear train having an annulus gear coupled to the planet-carrier of the first train, a sun wheel coupled to the sun wheel of the first train, and a planetcarrier serving as a reaction element and having rotatably mounted thereon planet wheels each meshing with the annulus gear and the sun wheel, a controllable stop for arresting rotation of the planet-carrier of the third train and thereby causing the first and third trains to operate compounded and to yield a low-speed ratio, a fourth planetary gear train having an annulus gear serving as a reaction member, a sun wheel coupled to the driving element, and a planetcarrier coupled to the driven element and having rotatably mounted thereon planet wheels, each meshing with the annulus gear and the sun wheel, a controllable stop for arresting rotation of the annulus gear of said fourth train and thereby providing an emergency low gear by the aid of the fourth train alone, a fifth planetary gear train adapted to yield a reverse ratio and having a sun wheel coupled to the driving element, an annulus gearcoupled to the driven element, and a planet-carrier serving as a reaction element and having rotatably mounted thereon planet wheels each meshing with the annulus gear and the sun wheel, and a controllable stop for arresting rotation of the planet-carrier of the fifth train.

9. A planetary multi-speed transmission having a driving element projecting from its front end and a driven element projecting from its rear end coaxially with-the driving element, the transmission also including a first planetary gear train having an annulus gear coupled to the driving element, a sun wheel serving as a reaction element, and a planet-carrier coupled to the driven element and having rotatably mounted thereon planet wheels each meshing with the annulus gear and the sun wheel, a second planetary gear train disposed behind the first train and having an annulus gear coupled to the sun wheel of the first train, a sun wheel serving as a reaction element, and a planet-carrier coupled to the driven element and having rotatably mounted thereon planet wheels each meshing with the annulus gear and the sun wheel, a controllable stop for arresting rotation of the sun wheel of the first train to yield and underdrive speed ratio, a controllable stop for arresting rotation of the sun wheel of the second train and thereby causing these trains to operate compounded and to yield an overdrive speed ratio, clutch means capable of locking these trains solid to yield a l-to-l ratio drive, a third planetary gear train disposed between said first and second trains and having an annulus gear coupled to the planet-carrier of the first train, a sun wheel coupled to the sun wheel of the first train, and a planet-carrier serving as a reaction element and having rotatably mounted thereon planet wheels each meshing with the annulus gear and'the sun wheel, a. controllable stop for arresting rotation of the planet-carrier of the third train and thereby causing the'first and third trains to operate compounded and to yield a low-speed ratio, a fourth planetary 'gear train disposed in front of the first train and having an annulus gear-serving as a reaction member, a sun wheel coupled to the driving element, and a planet-carrier coupled to the driven element and having rotatably mounted thereon planet wheels each meshing with the annulus gear and the sun wheel, a controllable stop for arresting rotation of the annulus gear of said fourth train and thereby providing an emergency low gear by the aid of the fourth train alone, a fifth planetary gear train disposed in front of said fourth train and adapted to yield a reverse ratio and having a sun wheel coupled to the driving element, an annulus gear coupled to the driven element, and a planet-carrier serving as a reaction element and having rotatably mounted thereon planet wheels each meshing with the annulus gear and the sun wheel, and a controllable stop for arresting rotation of the planetcarrier of the fifth train.

I ROBERT CECIL CLERK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,404,675 Wilson Jan.24, 1922 2,084,522 Cotal June 22, 1937 2,123,770 Cotal July 12, 1938 FOREIGN PATENTS Number Country Date 300,667 Great Britain Nov. 9, 1928 625,318 Great Britain June 24. 1949 

